Cardiac Arrest in a 31-Year-Old Man With Noonan Syndrome

J INVASIVE CARDIOL 2019;31(2):E40.

Key words: cardiac imaging, computed tomography, Noonan syndrome

A 31-year-old man with Noonan syndrome suffered an out-of-hospital cardiac arrest. Electrocardiogram (ECG) at return of spontaneous circulation (ROSC) showed ST-elevation in V1-V2, aVR, and lateral leads (Figure 1A). On arrival at our institution, the patient had severe postanoxic coma (Glasgow coma scale 3), but normalized ECG and stable hemodynamics.

Coronary angiography documented a giant right coronary artery (RCA) supplying collateral flow (Rentrop grade 3) to the left coronary artery (LCA), which presented a left main (LM) functional occlusion (Figures 1B and 1C; Videos 1-5). Chest CT scan revealed severe dilation of the pulmonary artery (PA) (38 mm), with a PA to ascending aorta diameter ratio of 1.22 (Figure 1D) and no signs of pulmonary embolism or aortic dissection. Transthoracic echocardiogram documented preserved global and regional left ventricular contractility, bicuspid aortic valve with moderate regurgitation, and dilation of the PA with mild pulmonary hypertension (PH). The scenario resembled that of patients with long-standing PH affected by ab-extrinseco compression of the LM due to a dilated PA. This anatomical picture has been previously described in a young patient with Noonan syndrome, although the dramatic clinical presentation (ie, cardiac arrest) seems unique.

Given the cardiovascular stability and severe neurological picture, we withheld emergent revascularization and started therapeutic hypothermia. Later, we learned that the patient had undergone percutaneous pulmonary valvuloplasty in childhood; his last cardiac control was at age 19 and showed mild dilation of the PA with normal pulmonary gradient. Unfortunately, the patient died 5 days later due to postanoxic encephalopathy complications.

View the Supplemental Videos here. 

From the ¹Cardiology Unit, Morgagni-Pierantoni Hospital, Forlì, Italy; and ²Cardiovascular Research Unit, Myriam Zito Sacco Heart Foundation, Forlì, Italy.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

The authors report that patient consent was provided for publication of the images used herein.

Manuscript accepted August 20, 2018.

Address for correspondence: Simone Grotti, MD, Cardiology Unit, Morgagni-Pierantoni Hospital, Cardiovascular Department AUSL Romagna, via Forlanini 34, 47121 Forlì, Italy. Email: grotti.simone@gmail.com